What’s the difference between that water main that ruptured near UCLA and the information pipeline that should be serving Department of Water and Power customers? Easy: The water main has been fixed.

The information flow is still broken.

A report by Staff Writer Mike Reicher, detailing many L.A. residents’ shock at getting huge bills to make up for months of underbilling, highlighted the DWP’s pathological failure to communicate. While the now 1-year-old computerized billing system was messed up, thousands of customers received estimated bills or no bills at all. And now they’ve been getting shockingly large bills, and even late fees — such as a San Pedro woman whose mid-August bill was for $1,395, nearly devouring her monthly Social Security check.

The bigger outrage is that the DWP didn’t give customers clear warnings about the possibility of backbreaking bills so they could budget for the expense and wasn’t ready for a deluge of phone calls seeking relief. Customers have been kept on hold for up to two hours.

If the DWP were a private-sector company, it could more easily beef up its customer-service force. But its hiring is bound by civil-service personnel rules, the city’s job-posting, application and testing procedures. City Council members had to intercede just to allow emergency hires to deal with the billing complaints.

DWP executives hope to have its call center adequately staffed by February, a full year after the crisis began.

This highlights something DWP General Manager Marcie Edwards told the Los Angeles News Group editorial board in the spring, at the start of her tenure and the news groups’ yearlong series of reports and editorials about the troubled department: The obstacles to improved DWP service are one-third city policies, one-third union obstinacy and one-third DWP management’s own doing.

Edwards rightly said her top priorities were improving customer service and fixing billing-system glitches. After five months, those items atop the to-do list remain undone, and there’s blame all around.

Apologies like the DWP’s latest on Wednesday are not enough. Every week that goes by without real solutions should make L.A. utility ratepayers angrier. Effective communication with customers is only becoming more vital amid efforts to fight water waste.

DWP and city leaders must act — with urgency — to ensure these failures never happen again.